This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082
Since dde_linux now contains the port of the Linux IP stack available for all
Genode base-* platforms move the repository out of drivers_arm and drivers_x86
build.conf to the optional build.conf (available to all platforms).
Norman Feske
Sebastian Sumpf
Alexander Boettcher
Christian Helmuth
Genode Labs